Gas feed device

ABSTRACT

A gas feed device for detecting trouble in a gas pressure sensor fitted to the gas feed device. The presence of trouble in pressure sensors is determined according to whether or not gas pressure values detected by the pressure sensors fitted to branch pipes is within an allowable range when stop valves fitted to the branch pipes connected to the access ports of hydrogen absorbing alloy tanks are fully opened from their fully closed state. When the gas feed device is mounted on a vehicle, no special operation is required for trouble detection because the trouble in the pressure sensors can be detected by fully opening the fully closed stop valves when the vehicle is started and normally the trouble can be judged by the mounted equipment.

This application is the National Phase of International ApplicationPCT/JP01/03906 filed May 10, 2001 which designated the U.S. and thatInternational Application was not published under PCT Article 21(2) inEnglish.

TECHNICAL FIELD

The present invention relates to a gas feed device, and moreparticularly to a gas feed device for feeding gas from a plurality ofgas tanks through feeding passages connecting to branch passages whichare in turn respectively connected to the plurality of gas tanks.

BACKGROUND ART

Conventional gas feed devices have been proposed for feeding hydrogenfrom a plurality of hydrogen absorbing alloy tanks to a hydrogen engine.The device proposed in Japanese Patent Laid-Open Publication No. Hei5-254353, for example, is provided with a stop valve and a pressuresensor in the vicinity of a supply port of each hydrogen absorbing alloytank to detect opening or closing of the stop valve by the pressuresensor.

However, such gas feed devices sometimes fail to detect the opening orclosing of the stop valve. Although opening or closing of the stop valveis sensed by the pressure sensor, opening or closing of the stop valvecannot be detected if the pressure sensor malfunctions. When thepressure sensor malfunctions, the amount of hydrogen remaining in thehydrogen absorbing alloy tank or the amount of hydrogen while hydrogenis being charged cannot be easily or accurately detected.

DISCLOSURE OF THE INVENTION

One object of the present invention is to provide a gas feed devicecapable of detecting trouble with a sensor or the like for detecting gaspressure. An additional object of the present invention is to provide agas feed device wherein trouble with a sensor or the like can bedetected while the device is normally operating.

In order to achieve one or more of these objects, the gas feed device ofthe present invention is configured as described below.

The gas feed device of the present invention is directed to a gas feeddevice for feeding gas from a plurality of gas tanks through feedpassages connected with branch passages which are in turn respectivelyconnected to the plurality of gas tanks, comprising stop valves fittedto the respective branch passages; gas pressure detection means whichare fitted to the respective branch passages on the side away from thestop valves and nearer the gas tanks; and trouble detecting means whichjudge a trouble of the gas pressure detecting means on the basis of theopening and closing actions of at least two stop valves among therespective stop valves and the gas pressure detected by the gas pressuredetecting means fitted together with the at least two stop valves.

The gas feed device of the present invention determines that there istrouble with the gas pressure detecting means related to the detectionon the basis of the opening and closing actions of at least two stopvalves among the stop valves which are fitted to the branch passagesrespectively connected to the plurality of gas tanks and the gaspressure which is detected by the gas pressure detecting means fittedtogether with the stop valves. Because trouble judgement is based on theopening and closing actions of at least two stop valves and the gaspressure detected at that time, it is not necessary to fit a specialdevice for detecting trouble, and trouble can be detected during normaloperation.

In this gas feed device of the present invention, the trouble judgementmeans may be configured so as to make a positive judgement concerningthe presence of trouble when the gas detecting means detect a gaspressure falling below, within a predetermined range, a predeterminedvalue which is determined according to the detected gas pressure amongthe gas pressure values detected by the gas pressure detecting means.Thus, presence of trouble in the gas pressure detecting means can bejudged with higher reliability.

In the gas feed device of the present invention, the plurality of gastanks can be tanks which have therein a hydrogen absorbing alloy andstore hydrogen. The gas feed device of the present invention can bemounted on a vehicle and configured to feed hydrogen from the pluralityof gas tanks to hydrogen consuming equipment mounted on the vehicle.Here, “hydrogen consuming equipment” includes a hydrogen engine, a fuelcell, and the like.

In the vehicle-mounted gas feed device of the present invention, stopvalve control means which fully close the stop valves of the pluralityof gas tanks when the vehicle operation is stopped and fully open thestop valves of the plurality of gas tanks when the vehicle is startedmay be provided, and the trouble judgement means may be configured so asto make a positive judgement concerning the presence of trouble when itis detected that the stop valves are fully opened when the vehicle isstarted. Thus, the trouble of the gas pressure detecting means can bejudged when the vehicle is started.

The gas feed device of the present invention may also be configured toadditionally comprise trouble output means which output a notificationconcerning the trouble when the trouble judgement means judge thepresence of trouble. This allows prompt action to be taken to deal withdetected trouble in the gas pressure detecting means.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a structural diagram schematically showing the structure of agas feed device 20 according to a vehicular mounted embodiment of thepresent invention.

FIG. 2 is a flowchart showing an example trouble judgement processroutine executed by an electronic control unit 60 of the gas feed deviceof FIG. 1.

BEST MODE FOR CARRYING OUT THE INVENTION

The best mode for carrying out the present invention will be describedwith reference to an example embodiment. FIG. 1 is a structural diagramoutlining the structure of the gas feed device 20 according to oneembodiment of the present invention. The gas feed device 20 according tothe present embodiment is mounted on a vehicle. The gas feed device 20of the embodiment is provided with hydrogen absorbing alloy tanks 22 to28 which can feed hydrogen to hydrogen consuming equipment 10, such as afuel cell or a hydrogen engine mounted on a vehicle, and an electroniccontrol unit 60 which controls the feed of hydrogen from the hydrogenabsorbing alloy tanks 22 to 28 as shown in the drawing.

The hydrogen absorbing alloy tanks 22 to 28 are connected to thehydrogen consuming equipment 10 via a feed pipe 40 through branch pipes32 to 38 which are connected to respective access ports. Stop valves 42to 48 which control the feeding of hydrogen from the respective hydrogenabsorbing alloy tanks 22 to 28 are fitted to the branch pipes 32 to 38.And, pressure sensors 52 to 58 for detecting a gas pressure in the pipesare fitted to the branch pipes 32 to 38 on the side away from the stopvalves 42 to 48 and nearer the tanks.

The electronic control unit 60 is configured as a microprocessor havinga CPU 62 at the core and provided with a ROM 64 which stores aprocessing program, a RAM 66 which temporarily stores data, and an I/Oport (not shown). Information such as gas pressure values P from thepressure sensors 52 to 58 is input to the electronic control unit 60 viainput ports. A drive signal to actuators 43 to 49 of the stop valves 42to 48 and a lighting signal to an indicator 68 are output from theelectronic control unit 60 through output ports.

Next, the operation of the gas feed device 20 of the embodimentconfigured as above, and particularly an operation to detect trouble inthe pressure sensors 52 to 58, will be described. FIG. 2 is a flowchartshowing an example routine for a trouble judgement process performed bythe electronic control unit 60 of the gas feed device 20 of theembodiment. This routine is performed when the vehicle is started.

When a routine for trouble judgement process is performed, the CPU 62 ofthe electronic control unit 60 performs processing of reading gaspressures Pc1 to Pc4 of the respective hydrogen absorbing alloy tanks 22to 28 with the stop valves 42 to 48 to be detected by the pressuresensors 52 to 58 in a fully closed state (step S100). Here, in theflowchart of FIG. 2, the gas pressures Pc1 to Pc4 to the respectivehydrogen absorbing alloy tanks 22 to 28 are simply indicated as “Pc”without their individual designations “1 to 4”.

The stop valves 42 to 48 are then fully opened (step S102), and gaspressures Po1 to Po4 are read are measured by the pressure sensors 52 to58 (step S104). A comparison gas pressure Ps used to judge trouble inthe read gas pressures Po1 to Po4 is then determined (step S106). Thegas pressure Ps can be determined as an average value by, for example,selecting three values having a small deviation from among the valuesfor gas pressures Po1 to Po4.

After the comparison gas pressure Ps has been determined, respectivedeviations of the comparison gas pressure Ps and the gas pressures Po1to Po4 are compared with a threshold Pr (step S108). Here, the thresholdPr is determined as an allowable error with respect to the pressuresensors or a value slightly larger than that. When any deviation exceedsthe threshold Pr, it is judged that trouble has occurred in the pressuresensor which has detected the gas pressure Po related to the pertinentdeviation, then the relevant indicator 68 is illuminated to output thetrouble (step S110), and this routine is terminated. When everydeviation is equal to or below the threshold Pr, it is judged that notrouble can be found in any of the pressure sensors 52 to 58, and thisroutine is terminated.

Trouble in any of the pressure sensors 52 to 58 can be detected with thegas feed device 20 of the embodiment described above. A specialoperation for judging trouble is not necessary because trouble is judgedduring the normal operation for starting the vehicle. The judgment ofthe trouble is made on the basis of the opening and closing action ofthe stop valves 42 to 48, which are normally fitted to the hydrogenabsorbing alloy tanks 22 to 28, and the gas pressure values from thepressure sensors 52 to 58, which are normally fitted to the hydrogenabsorbing alloy tanks 22 to 28. Therefore, provision of another sensoror the like for trouble judgement is unnecessary.

Although the example gas feed device 20 of the embodiment judges atrouble of the pressure sensors 52 to 58 by fully opening the stopvalves 42 to 48 which are fully closed when the vehicle is started, thepresent invention is not limited to a configuration in which judgementis made when the vehicle is started. Trouble with the pressure sensors52 to 58 can, for example, be judged anytime the fully closed stopvalves 42 to 48 are fully opened.

And, although the gas feed device 20 of the illustrative embodimentjudges trouble of the pressure sensors 52 to 58 by fully opening all ofthe fully closed stop valves 42 to 48, the device may be configured tosimultaneously open two or more stop valves among the fully closed stopvalves 42 to 48 and to judge trouble of the pressure sensors which aremounted together with the opened stop valves related to the opening onthe branch pipes. With such a configuration, when three or more stopvalves are opened or closed, the comparison gas pressure Ps may bedetermined from two or more gas pressures Po having a small deviationamong them and, when two stop valves to be opened or closed, one of themmay be determined as the comparison gas pressure Ps to judge thetrouble. In such a case, it cannot be judged which pressure sensor isthe source of the trouble, but it can be judged that there is troublewith at least one of the pressure sensors.

The example gas feed device 20 of the preferred embodiment is configuredto feed hydrogen from the hydrogen absorbing alloy tanks 22 to 28, buthydrogen may be fed from a hydrogen tank not incorporating a hydrogenabsorbing alloy. The present invention may also be applied to a devicefor feeding gas other than hydrogen.

Also, while the in the embodiment, a vehicular mounted gas feed device20 has been described, this is not a requirement of the presentinvention, which may be configured as, or used with, a device notmounted on any type of vehicle.

In general, while there has been described the embodiment for the modeof carrying out the present invention, it is to be understood that thepresent invention is not limited to the embodiment and can be carriedout in various modes without departing from the point of the presentinvention.

INDUSTRIAL APPLICABILITY

This gas-feed device may be used for an apparatus which feeds hydrogento a hydrogen engine, a fuel cell, or the like mounted on a vehicle.

1. A gas feed device for feeding gas from a plurality of gas tanksthrough feed passages communicated with branch passages which arerespectively connected to the plurality of gas tanks, comprising: stopvalves mounted on the respective branch passages; gas pressure detectionmeans which are fitted to the respective branch passages on the sideaway from the stop valves and nearer the gas tanks; and troublejudgement means which judge a trouble of the gas pressure detectingmeans on the basis of the opening and closing actions of at least twostop valves among the respective stop valves and the gas pressuredetected by the gas pressure detecting means fitted together with thestop valves.
 2. The gas feed device according to claim 1, wherein, inconnection with values detected when a plurality of stop valves relatedto the opening and closing operations are opened, the trouble judgementmeans make a positive judgement concerning the presence of trouble whenthe gas detecting means detect a gas pressure falling below, within apredetermined range, a predetermined value which is determined accordingto the detected gas pressure among the gas pressure values detected bythe gas pressure detecting means.
 3. The gas feed device according toclaim 1 or 2, wherein the plurality of gas tanks are tanks whichincorporate a hydrogen absorbing alloy and store hydrogen.
 4. The gasfeed device according to claim 3, wherein the gas feed device is avehicular mounted gas feed device for feeding hydrogen from theplurality of gas tanks to hydrogen consuming equipment mounted on avehicle.
 5. The gas feed device according to claim 4, wherein: stopvalve control means are provided to fully close the stop valves of theplurality of gas tanks when the vehicle operation is stopped and tofully open the stop valves of the plurality of gas tanks when thevehicle is activated, and the trouble judgement means make a positivejudgement concerning the presence of trouble when it is detected thatthe stop valves are fully opened when the vehicle is started.
 6. The gasfeed device according to claim 1, further comprising: trouble outputmeans for outputting a trouble notification when the trouble judgementmeans make a positive judgement concerning the presence of trouble.
 7. Avehicle comprising the gas feed device according to claim
 1. 8. A gasfeed device for feeding gas from a plurality of gas tanks through feedpassages communicated with branch passages which are respectivelyconnected to the plurality of gas tanks, comprising: stop valves mountedon the respective branch passages; gas pressure detectors which arefitted to the respective branch passages on the side away from the stopvalves and nearer the gas tanks; and an electronic control unitconfigured to judge a trouble of the gas pressure detectors on the basisof the opening and closing actions of at least two stop valves among therespective stop valves and the gas pressure detected by the gas pressuredetectors fitted together with the stop valves.
 9. The gas feed deviceaccording to claim 8, wherein, in connection with values detected when aplurality of stop valves related to the opening and closing operationsare opened, the electronic control unit makes a positive judgementconcerning the presence of trouble when the gas detectors detect a gaspressure falling below, within a predetermined range, a predeterminedvalue which is determined according to the detected gas pressure amongthe gas pressure values detected by the gas pressure detectors.
 10. Thegas feed device according to claim 8 or 9, wherein the plurality of gastanks are tanks which incorporate a hydrogen absorbing alloy and storehydrogen.
 11. The gas feed device according to claim 10, wherein the gasfeed device is a vehicular mounted gas feed device for feeding hydrogenfrom the plurality of gas tanks to hydrogen consuming equipment mountedon a vehicle.
 12. The gas feed device according to claim 11, wherein:stop valve actuators are provided to fully close the stop valves of theplurality of gas tanks when the vehicle operation is stopped and tofully open the stop valves of the plurality of gas tanks when thevehicle is activated, and the electronic control unit makes a positivejudgement concerning the presence of trouble when it is detected thatthe stop valves are fully opened when the vehicle is started.
 13. Thegas feed device according to claim 8, further comprising: an indicatorconfigured to output a trouble notification when the electronic controlunit makes a positive judgement concerning the presence of trouble. 14.A vehicle comprising the gas feed device of claim 8.